The invention herein described was made in the course of or under a contract with the United States Air Force Systems Command.
The invention relates to the catalytic homopolymerization of norbornadiene, hereinafter referred to as NBD. Particularly the invention relates to the preparation of a solid polymer using nickel acetylacetonate or a specified nickel-phosphine complex. The polymer can be used as a solid high energy fuel.
Norbornadiene is also known as bicyclo-(2.2.1) heptadiene-2,5. A method of preparation is disclosed in U.S. Pat. No. 2,875,256 issued Feb. 24, 1959. Hereinafter, norbornadiene is referred to as NBD. The latter can be represented by either one of the following structural formulas: ##STR1##
J. P. Kennedy et al in Polymer 6, 1965, in an article titled "Cationic Transannular Polymerization of Norbornadiene" discloses polymerization of NBD using an aluminum chloride catalyst in ethyl chloride and methylene chloride solvent at temperatures ranging from -123.degree. C to +40.degree. C. M. B. Roller et al in Journal of Applied Polymer Science, Vol. 17, 1973, "Thermomechanical Behavior of a Polynorbornadiene" reports similar results. The yield of NBD polymer reported by the aforementioned references were in the order of 10-20 weight percent.